From: Jan Beulich Date: Thu, 16 Feb 2006 22:41:55 +0000 (+0100) Subject: [PATCH] x86_64: make touch_nmi_watchdog() not touch impossible cpus' private data X-Git-Tag: v2.6.16-rc4~38 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=99019e919969be88e7e4042f3afa296bd55ad9ec;p=linux-2.6 [PATCH] x86_64: make touch_nmi_watchdog() not touch impossible cpus' private data Along with that, also suppress the memory touching altogether when the watchdog is not running, to eliminate needless crosstalk. Plus ad a call to it to make things consistent (one could also consider removing the call in enable_timer_nmi_watchdog()). Signed-off-by: Jan Beulich Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index 8be407a1f6..5bf17e41cd 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -236,6 +236,7 @@ static void enable_lapic_nmi_watchdog(void) { if (nmi_active < 0) { nmi_watchdog = NMI_LOCAL_APIC; + touch_nmi_watchdog(); setup_apic_nmi_watchdog(); } } @@ -456,15 +457,17 @@ static DEFINE_PER_CPU(int, nmi_touch); void touch_nmi_watchdog (void) { - int i; + if (nmi_watchdog > 0) { + unsigned cpu; - /* - * Tell other CPUs to reset their alert counters. We cannot - * do it ourselves because the alert count increase is not - * atomic. - */ - for (i = 0; i < NR_CPUS; i++) - per_cpu(nmi_touch, i) = 1; + /* + * Tell other CPUs to reset their alert counters. We cannot + * do it ourselves because the alert count increase is not + * atomic. + */ + for_each_present_cpu (cpu) + per_cpu(nmi_touch, cpu) = 1; + } touch_softlockup_watchdog(); }